A speed limit of 40 to 50mph will be in force on the A34 Oxford western bypass while an ageing viaduct is replaced.

Residents in neighbouring Wolvercote have been warned they face some noise disturbance when work starts in August on the two-year, £40m operation to rebuild the Wolvercote viaduct.

The existing structure, built in 1960-61, needs to be replaced to ensure it meets current standards.

An exhibition explaining how the reconstruction will take place was held at Wolvercote Young People's Club, in St Peters Road, today (Friday), and there is another chance to view it tomorrow.

Highways Agency project manager Martin Potts said: "The beautiful thing about this scheme is that we keep the dual carriageway running throughout and we don't believe an alternative route is needed.

"We plan to replace the A34 Wolvercote viaduct while ensuring that we minimise disruption to drivers and cause minimal impact on the local environment."

But resident Graham Jones, of Rosamund Road, Wolvercote, one of the streets closest to the viaduct, said: "Residents are concerned about the noise levels.

"We're also concerned about traffic choosing to come through Wytham and Wolvercote to avoid the speed restrictions and the work taking place on the A34.

"The A34 is already struggling to cope with the amount of traffic it has to take and I wonder what the hold-ups will be like if an accident happens while this work is taking place. I believe the Highways Agency needs to consider a suitable alternative route for drivers."

Birute Mazeika, 48, who lives in Rosamund Road with her family, said: "We're very unhappy about this and will consider moving if the noise is too bad."